Wafer level optical module

Abstract

An optical module may be formed on a wafer. The wafer may include a substrate and one or more optical components encapsulated, at least partially, by the substrate. Each of the optical components are configured to emit or sense light. The wafer may also include one or more printed circuit board (PCB) bars encapsulated, at least partially, by the substrate allowing electrical conductivity from a first side of the substrate to a second side of the substrate. The wafer may also include at least one redistribution layer to electrically couple at least one of the optical components to at least one of the PCB bars.

What is claimed is: 
     
       1. An optical wafer comprising:
 a substrate; 
 one or more optical components encapsulated, at least partially, by the substrate, wherein each of the one or more optical components comprises an active side exposed on a first side of the substrate and configured to emit or sense light; 
 a passivation layer disposed on the first side of the substrate and over at least a portion of the active sides of the one or more optical components such that:
 the active sides of the one or more optical components are exposed via a recess formed within the passivation layer; and 
 the passivation layer forms a sidewall of the recess configured to act as an optical barrier between the one or more optical components; 
 
 a dark photoresist layer, disposed on the passivation layer and the sidewall of the recess formed within the passivation layer, configured to reduce optical interference between the one or more optical components; 
 one or more printed circuit board (PCB) bars encapsulated, at least partially, by the substrate, wherein the one or more PCB bars are configured to allow electrical conductivity from the first side of the substrate to a second side of the substrate; and 
 at least one redistribution layer configured to electrically couple at least one of the one or more optical components to at least one of the one or more PCB bars. 
 
     
     
       2. The optical wafer of  claim 1 , wherein the one or more optical components comprises one or more light emitting diodes (LEDs), one or more photodiodes, or any combination thereof. 
     
     
       3. The optical wafer of  claim 2 , wherein the one or more LEDs comprises a plurality of LEDs and the one or more photodiodes comprises a plurality of photodiodes, wherein the plurality of photodiodes are arranged circumferentially around the plurality of LEDs. 
     
     
       4. The optical wafer of  claim 1 , comprising a plurality of passivation layers configured to provide electrical isolation between electrical connections within the optical wafer. 
     
     
       5. The optical wafer of  claim 1 , comprising a plurality of external electrical connections configured to couple the optical wafer to an electronic device. 
     
     
       6. The optical wafer of  claim 5 , wherein the external electrical connections comprise an under-bump metallization layer or a solder bump, or both. 
     
     
       7. The optical wafer of  claim 5 , comprising a cover configured to be integrated into an enclosure of the electronic device and configured to allow optical communication between the one or more optical components and an environment of the enclosure. 
     
     
       8. The optical wafer of  claim 1 , comprising a lens configured to focus light into or out of at least one of the one or more optical components. 
     
     
       9. The optical wafer of  claim 8 , wherein in the lens comprises a Fresnel lens. 
     
     
       10. The optical wafer of  claim 1 , wherein each of the one or more optical components is exposed via separate respective recesses formed in the passivation layer. 
     
     
       11. An optical module comprising:
 a wafer comprising:
 a substrate having a first side and a second side; 
 a plurality of optical components encapsulated, at least partially, by the substrate, wherein the plurality of optical components comprises one or more light sources and one or more light sensors, wherein each of the plurality of optical components comprises an active side exposed on the first side of the substrate; 
 a passivation layer disposed on the first side of the substrate and over at least a portion of the active sides of the plurality of optical components such that:
 the active sides of the plurality of optical components are exposed via a recess formed within the passivation layer; and 
 the passivation layer forms a sidewall of the recess configured to act as an optical barrier between the plurality of optical components; and 
 
 a dark photoresist layer disposed on the passivation layer and the sidewall of the recess formed within the passivation layer that reduces optical interference between the plurality of optical components; and 
 
 a cover configured to protect the wafer from an environment. 
 
     
     
       12. The optical module of  claim 11 , wherein the wafer comprises one or more printed circuit board (PCB) bars configured to electrically couple an electrical contact of at least one of the plurality of optical components on the first side of the substrate to a communication contact on the second side of the substrate opposite the first side of the substrate. 
     
     
       13. The optical module of  claim 11 , wherein the cover is configured to secure the optical module to an electronic device and allow optical communication between the optical module and the environment outside of the electronic device. 
     
     
       14. The optical module of  claim 11 , wherein the cover comprises a lens configured to focus or diffuse light emitted from the one or more light sources or light received by the one or more light sensors. 
     
     
       15. The optical module of  claim 11 , wherein each of the plurality of optical components is exposed via separate respective recesses formed in the passivation layer. 
     
     
       16. A wearable device comprising:
 an enclosure; 
 an optical module disposed in the enclosure, the optical module comprising:
 a wafer comprising a substrate; 
 one or more optical components surrounded, at least partially, by the wafer, wherein each of the one or more optical components are configured to emit or sense light via an active side of the one or more optical components; 
 one or more printed circuit board (PCB) bars surrounded, at least partially, by the wafer, wherein the one or more PCB bars are configured to electrically couple a contact of at least one of the one or more optical components to one or more contacts through the wafer; 
 a passivation layer disposed on a first side of the substrate and over at least a portion of the active sides of the one or more optical components such that:
 the active sides of the one or more optical components are exposed via a recess formed within the passivation layer; and 
 the passivation layer forms a sidewall of the recess configured to act as an optical barrier between the one or more optical components; and 
 
 a dark photoresist layer disposed on the passivation layer and the sidewall of the recess formed within the passivation layer that reduces optical interference between the one or more optical components; and 
 
 a processor disposed within the enclosure, electrically coupled to the one or more optical components via the one or more contacts, and configured to communicate electrical signals with the one or more optical components. 
 
     
     
       17. The wearable device of  claim 16 , wherein the enclosure comprises a transparent portion configured to allow optical communication between the one or more optical components and an environment outside the enclosure. 
     
     
       18. The wearable device of  claim 17 , wherein the transparent portion of the enclosure is configured to rest against a user's skin when in operation. 
     
     
       19. The wearable device of  claim 16 , wherein the one or more optical components comprises one or more light sources and one or more light sensors, and wherein the one or more light sources are configured to illuminate a subject and the one or more light sensors are configured to sense a response to illumination. 
     
     
       20. The wearable device of  claim 16 , wherein the wearable device comprises a watch.